Abstract: An easy retrofitting of a night vision thermal imager to mount a television TV) camera thereon which allows the thermal imager outputs to be viewed remotely by a CRT display. The retrofitting provides a compact and utilitarian remote viewing capability without altering the imager itself. An unpluggable mirror unit, positioned at the output of the imager, provides a folded light path allowing the TV camera to be mounted in an inverted position over the viewer and operate as a remote observation station with the mirror unit attached, or be viewed directly with the mirror unit removed.

Abstract: By rotating a diaphragm in front of a pickup device, for example a pyroelectric vidicon, eddy currents are generated in the diaphragm if the diaphragm is made of a metal. These eddy currents are generated as a result of the interaction between the moving diaphragm and the magnetic field of the deflection coils of the vidicon. If the diaphragm is instead made of an insulating material, separation of charges occurs on it as a result electrostatic generation, due to the interaction between the diaphragm and the electrostatic field of the vidicon. Compensation of the charge separation causes interference in the video signal. According to the invention a diaphragm of an insulating material is used which is covered with a pattern of electrically conductive tracks or a very high resistance layer. As a result of this no eddy currents and no noteworthy electrostatic charges can occur, so that an interference-free video signal is obtained.

Abstract: The invention relates to a technique for providing a so-called `pedestal` voltage on the rear surface of the target of a pyroelectric camera. This is a positive voltage required to ensure efficient discharge, by the electron beam, of the pyroelectric charge. In the invention, the pyroelectric material is in the form of a plurality of islands of pyroelectric material connected individually to the signal plate. Each island is coated on its rear surface and on at least one side, by a conductive film. By applying a positive bias voltage to the signal plate, the rear surface of the pyroelectric islands are similarly biassed to provide the pedestal.

Abstract: A thermal image exposure plate is disclosed having a grid pattern on one side thereof exposed to thermal radiation. The grid pattern depth is less than a thickness of the plate. High image resolution and image sensitivity results. The plate is useful in thermal image exposure devices, particularly in a pyroelectric picture tube.

Abstract: In a forward-looking infared system of the type in which a cryogenically led infared detector array drives a light-emitting array whose video output is focused onto the target of an electro-optical multiplexer, such as a vidicon tube, which drives a CRT display, the video chain may be tested without cool-down of the infared detector. A point-source of light, such as a tungsten lamp mounted forward of and at the side of the vidicon target, is energized to project light onto the target surface at an acute angle, setting up a gradient of light intensity across each of the horizontally scanned lines.

Abstract: A camera tube for thermal imaging is disclosed comprising an entrance window of an electrically conductive material, a target for converting the thermal image, and an electron beam system for scanning the target. Incident thermal radiation is modulated by means of a mechanical chopper functioning as a modulator directly in front of the entrance window. The entrance window is electrically isolated from the target and is preferably grounded. By so doing, the target is shielded against electrical influences due to the modulator.

Abstract: A compact modularized go-no-go resolution tester is provided for use with /PVS-5 image intensifier goggles. The tester can be quickly disassembled and reassembled by operators having little or no skill and training to replace broken or expendible parts thereof. Prior adjustments of the devices are not affected by disassembly and such adjustments are easily performed.

Abstract: A guided bomb for use in low level flying for pinpoint target combat, comprises a bomb having a braking device associated therewith to produce a slow-down which is effective against the trajectory and a picture-taking sensor connected to the bomb to guide the bomb for final phase guidance. The braking device advantageously comprises retrorockets or a parachute. The picture-taking sensor is advantageously a television camera or an infrared camera and a tracker is associated with it which may be mounted, for example, on the aircraft carrying the bomb. The picture taken by the picture-taking sensor is transmitted via either a radio or mechanical connection to the aircraft and is reproduced there for guidance by the pilot. The target may advantageously be illuminated by a laser illuminator carried on the aircraft and the bomb advantageously has a tracker with laser vectoring.

Abstract: A signal processing method for eliminating fixed error sources in the video signal of a pyroelectric vidicon comprising the step of adding the signal value at each point of the pyroelectric plate to previous signal values relating to the same point for forming an integrated or mean value for a great number of signal values at each point and then subtracting the fixed error estimate from the signal values in the latest received video signal. This mean value, if differing from zero, is the estimate of the fixed error at the respective point.

Abstract: The light which is emitted from the output screen of an image intensifier and passed through a subsequent output objective, is converted into an electrical signal by means of a photomultiplier tube or an image pick-up tube. The noise or modulation content of the electrical signal are measured. An optimum adjustment of the focussing position of the output objective and the magnitude of the focussing voltage applied to the imge intensifier, cause the noise or modulation content to attain an extreme value, e.g. a maximum. The focussing voltage and the focussing position of the output objective are iteratively adjusted.

Abstract: A collinear aiming light image viewer device in a common housing through ch an observer may view both a target scene and a superimposed collinear aiming light beam within the viewer. The aiming light source is positioned in an offset area of the common housing to project a narrow IR beam off a partially reflective mirror along a portion of the optical axis of the image viewer onto a scene wherein the scene and IR beam images are simultaneously viewed through an image intensifier.

Abstract: A device for binocular viewing of residual light in the visible and the near infrared spectrum, comprising an optical input system, at least one singular image intensifier of the non-inverting type, a collimator, two ocular paths parallel with the axis of the device, and an optical output system associated with each ocular path, which is arranged so that a single image inversion is performed in each ocular path.

Abstract: An improved binocular night glass suitable for use with infrared light and relatively low levels of visible light without changing the viewing system, in particular its prism system. According to the invention the improvement comprises that the image converter includes two image conversion tube sections, only one of which results in image reversal.

Abstract: A method and a device for analyzing a pyroelectric target in an evacuated envelope. The target with two opposite faces has a first face disposed towards a zone of the envelope which is transparent to an incident radiation. The second face is orientated towards an electron gun generating device which operates at least one electron beam. A first scanning of the pyroelectric target with a high intensity low resolution electron beam allows a stage of neutralization of the electron charges induced in the target by the incident radiation. The stage of neutralization is to be considered as effecting a storage of the signal recorded on the target. A second scanning of the pyroelectric target with an electron beam of high resolution and low intensity corresponds to a stage of read-out proper of the target.

Abstract: The present method provides a determination of physical characteristics of materials. For example, the granulometry of a falling or flowing stream of disperse material may be analytically determined by a heat image camera cooperating with a memory such as a screen type image storage, a monitor, and a process computer such as a microcomputer which compares the measured values with a reference value to provide a control signal. A control apparatus regulates the flow rate of the material stream, such as aggregate, in response to said control signal. The present method may be used to determine, for example, the size of falling liquid droplets or the size of the particles of granular material which is stationary in a measuring zone or space.

Abstract: A zoom system is provided which utilizes wide angle and narrow angle vidicon cameras, a display and an electronic system under an operator's control which operates to blend and magnify signals from the cameras so as to provide the viewer with a zoom capability for the display without effective loss of resolution.

Abstract: Process and arrangement for reconstituting the signal representing the thermal flux absorbed by a pyroelectric target, the arrangement being used in infrared camera tubes. It comprises means for correcting the signal Sn for reading a point of co-ordinates x, y of the target, during a frame of order n, comprising means for calculating a first component representing the Laplacian of the signal Sn and means for summating the signal Sn with the first component. The correcting means deliver a corrected signal. Means for generating a complementary signal are connected to the output of the calculating means and comprise means for generating a signal representing the temperature .theta..sub.n-1 of the point of co-ordinates x, y during the reading of that point in the course of a frame of order n-1 and a second component representing the Laplacian of that temperature. Means for summating the complementary signal with the corrected signal deliver the reconstituted signal.

Abstract: An afocal spectral converter as adaptor for existing aiming and sighting devices for the conversion for instance of a heat picture into a visible picture. The arrangement includes the combination of an infrared picture receiving unit with a picture reproducing unit in such a way that the entire system has the enlargement 1:1. The connection of the adaptor with the main device is such that the optical axis of the picture receiving unit is parallel to the optical axis of the main device, and the parallel ray bundle of the picture reproducing unit is so imaged into the main device that the latter will not be influenced.

Abstract: Two pyroelectric vidicons are adapted to alternately receive infrared ene radiated from an object by means of a rotating half circle mirror and fixed mirror arrangement. The alternations of the infrared energy received between the two vidicons are synchronized by means of a synchronization and drive circuit adapted to receive frame sync pulses from the camera circuitry. By this arrangement, information is received by the camera 100% of the time.

Abstract: Infrared pick-up device comprising an infrared sensitive television pick-up tube and a diaphragm, which is alternately in the open and closed state, the amplitude of the available video signal being proportional to the speed at which the temperature changes, an additional, uniform radiation being superimposed on the scene radiation which can be changed so by a signal processing stage connected to the pick-up tube that the quantity of the average scene radiation plus the superimposed additional radiation is substantially equal to the radiation coming from the diaphragm in the closed state and acting on the target plate of the pick-up tube.

Abstract: An imaging system for detection of a target is provided which compensates for range dependency of a reflected interrogating signal. The imaging system includes an electromagnetic radiation source for generating a series of interrogating pulse signals directed towards the target. A receiver is triggered for receiving the reflected interrogating pulse signals from the target during variable time intervals and for generating a resultant output signal. The receiving time intervals are varied such that the number of reflected interrogating pulse signals received by the receiver is dependent on the distance between the receiver and the target. The receiver thus generates a constant amplitude resultant output signal independent of the distance between the receiver and target.

Abstract: An imaging system for detection of a target is provided which compensates for range dependency of a reflected interrogating signal. The imaging system includes an electromagnetic radiation source for generating a series of interrogating pulse signals directed towards the target. A receiver is provided and operable to be triggered for receiving during preselected time intervals the reflected interrogating pulse signals from the target and for generating a resultant output signal. The system further includes circuitry connected for triggering the receiver to receive reflected interrogating pulse signals according to a predetermined time function. The number of reflected interrogating pulse signals thus received by the receiver is dependent on the distance between the receiver and the target. The receiver thus generates a resultant output signal to provide a signal of constant amplitude independent of the distance between the receiver and target.

Abstract: 1. Optical apparatus, comprising:A concave, substantially spherical reflecting surface;An image intensifier along the optical axis of said reflecting surface and having entrance and exit image faces, said exit face being substantially coincident with the focal surface of said reflecting surface;An optical objective system for producing an image substantially coincident with the entrance face of said image intensifier; andA partially reflecting, partially transmitting beamsplitter interposed between said image intensifier and said reflecting surface.

Abstract: An improved a.c. coupled forward looking infrared (FLIR) system is disclosed. In a.c. coupled FLIR systems utilizing an array of detectors, the video signals produced when scanning "hot targets" are distorted toward the dark end of the display dynamic range. This distortion produces dark image obliterating streaks which are substantially reduced by a streak reduction system. In one embodiment video signals for each scan line are delayed in a delay line; while, the mean voltage is determined in an integrator, the mode voltage calculated from the probability density curve and the two summed in an adder to provide a video correction voltage. A sample and hold circuit then applies the video correction signal to the video voltage output of the delay line to produce video signals absent any streaking voltage. In another embodiment the video signals are connected to a first integrator to determine the mean voltage.

Abstract: The present invention is an apparatus for detecting a surface flaw in hot metal including a particularly designed television camera, a shutter means and a control circuit which compensates the television camera's shading as well as the temperature difference among normal parts of the observed material.The apparatus makes it possible to conduct clear detection of a flaw on the surface of the hot material as it is so that yield loss at the time of scarfing can be avoided while heat energy can effectively be utilized.

Abstract: A device for jamming or damaging an enemy's infrared detection apparatus consists of the following equipment mounted on a tripod which is adjustable in azimuth and elevation: a multiple rod laser head emitting coherent light at more than one wavelength, an aiming telescope, a proximity focused image converter telescope, and an integrating image tube. The laser head is provided with a Q switch and collimating optics; the integrating image tube being adjustably mounted on the tripod so that it can be separately set for boresighting with the other instruments. In place of the laser head a generator of X-band microwave energy can be substituted.

Abstract: The invention relates to periscopic apparatus for the observation and aiming or sighting apparatus, particularly for mounting on a vehicle, having a stabilized panoramic gunsight head positioned externally of the vehicle and a corresponding sight tube with at least one eye piece positioned within the said vehicle. The sight tube and the gunsight head are interconnected by a wall-traversing periscopic ferrule which can be substituted by a sleeve in which is placed either a nocturnal vision means or a ranging means or both of the said means.

Abstract: A method for electrically reading a target such as a pyroelectric one, in a camera tube. It consists in the repetition of a sequence of three phases: reading by an electron beam scanning process, compensation by secondary electron emission and levelling of the potential of the target, the duration of each of the phases being substantially equal to the duration of an analysis line of the target. The last two phases are provided for lines preceding the line read respectively by numbers p and k of lines with p<k.

Abstract: A thermal retina disposed in a vacuum envelope receives thermal radiation emitted from an object being viewed includes a semiconductor bolometric thin film target, a metallic heat sink mesh disposed between the thermal radiation and the target to support the target where the heat sink mesh has webs to define web areas of the target and holes surrounded by the webs to define hole areas of the target and a contacting electrode disposed over the holes connecting the film target in the holes to the webs. A readout scanning electron beam is generated in the envelope to provide on the electrode an electric signal proportional to the resistance of the target due to the thermal radiation in the web areas and proportional to the resistance of the target due to the thermal radiation in the hole areas.

Abstract: 1. A photoconductive target for a pickup tube comprising a layer of porous lead telluride on a transparent conductive layer, said porous lead telluride having a resistivity of approximately 10.sup.-11 ohm cm when maintained at a temperature substantially equal to liquid nitrogen temperature.

Abstract: An imaging device for detecting reflections of millimeter waves from a tat. The imaging device includes a composite cathode for converting an input radiation image to an electron image by field emission, a focusing lens to demagnify the image, and an amplifier and storage plate spaced from the composite cathode for detecting, storing and transferring the electron image to a viewing screen or recording medium.

Abstract: A method of operating a pyroelectric camera tube having a normally provided electron beam emitting cathode and control grid G.sub.1 controlling the electron beam, and a gas in the interior space of the tube by applying positively-going pulses to the grid G.sub.1 during the period of the normally applied line blanking pulses. A circuit for producing the positively-going pulses is also disclosed which have the effect of increasing the target pedestal potential.

Abstract: An infrared vidicon system having capacitive type target elements is provided with a means for modulating the target scene with a duty cycle of less than 50% and the reading of the target scene in a predetermined sequence when modulation is not being applied to the vidicon tube. The sequentially read target scene is stored and continuously played back to prevent flicker. This operation allows signal buildup, because the target scene is not discharged every frame.This vidicon system also reduces the non-uniformity of responsivity across the surface of the target of the tube by illuminating the target by an adjustable uniform source of infrared radiation.

Abstract: An infrared chopper device for use with a starting thermal imaging system, uch as a pyroelectric vidicon, is provided which utilizes liquid crystal technology.

Abstract: Disclosed is an infrared radiation (IR) sensor and imaging tube employing same wherein the sensor includes a pyroelectric substrate having a conductive layer of infrared radiation absorbing material on one surface thereof. An electron-emissive metallic grid is disposed on the opposite surface of the pyroelectric substrate and is configured to expose predefined discrete areas of the pyroelectric substrate at which radiation-dependent voltages are developed. These voltages permit the metallic grid to emit electrons in quantity proportional to the infrared radiation received by the radiation absorbing material and the pyroelectric substrate. This IR sensor may advantageously be incorporated in a thermal imaging tube which includes means for flooding the grid surface of the pyroelectric substrate with photons and means for accelerating electrons emitted therefrom to a suitable target, such as a charge coupled device (CCD), a phosphor, a silicon intensified target (SIT), or other suitable electron collector.

Abstract: In camera using resistive targets wherein a recording tube of which the target (100) made of a pyroelectric material in the example and read by a beam of electrons, permanently receives a flow of ions formed in the tube by the collision between the electrons of the beam and the atoms of a gaseous mass of which the pressure in the tube is determined by the temperature of a reservoir, the invention provides means for controlling the temperature of the reservoir (filament 03) in dependence upon the average target current which is proportional to the flow of ions in question.

Abstract: The camera includes an input focussing and image cycling system to alternly cycle between a thermal reference and a thermal image, onto a thermally sensitive layer. Means are provided for electronically controlled conversion of thermal images to electron images. Further means, defined in the camera, accomplish electronic image integration and storage. The output portion of the camera includes means to furnish image intensification, after integration and storage. Photographic or electrostatic film is pulled at a constant rate by a drive system positioned at the output of the camera, to expose film to the intensified image.

Abstract: In a pyroelectric vidicon, the target is covered with a layer of vacuum compatible material which has a high secondary emission coefficient, a low first cross-over and low conductivity to prevent decomposition of the target.

Abstract: A pyroelectric radiation detector which is relatively immune to the effects of microphonic vibrations includes within an evacuated envelope a triglycine sulphate (TGS) target secured by silicone grease to a thin (3-6 .mu.M) mica support plate. The mica support plate is adhesively secured by means of an enamel to a titanium annulus which, in turn, is epoxied to the window of the evacuated envelope. The coefficients of expansion of the annulus and the support plate are selected such that after they are joined on to the other the support plate is stretched tightly across the annulus and therefore has a natural period substantially higher than the natural period of the annulus which supports it.

Abstract: The invention contemplates improvement in the interpretability of heat-detection data, resulting from scanning a field. One or more heat-detecting devices are caused to scan the field and to create light modulation, superposed on a monitoring display of the field, the monitoring display being the product of observing the field in a band (e.g. visible light) other than that of the scanned heat response. The result is to superpose on the monitoring display brightened light modulations in accordance with heat sources encountered in the course of heat scanning the same field.

Abstract: 1.

Abstract: A pyroelectric camera tube having a high resistivity target is operated by applying an increasing ramp voltage to the target so as to provide a pedestal potential which permits objects producing a negative change in temperature to be viewed and then pulsing the target to neutralise the resultant electric field established between the signal and electron beam scanned surfaces of the target. Thus during the rising ramp voltage the tube operates in a cathode potential stabilised mode and at the end of the ramp the target is pulsed to operate the tube in an anode potential stabilised mode. Since the pedestal voltage is provided by the ramp voltage the tube may be substantially evacuated.